I am trying to dissolve a 1 gram gold coin I have to make colloidal gold. It is hard to source nitrates for aqua regia, although there is poor man's aqua regia using alternate nitrate sources. I found another recipe online, which is easier as I have the ingredients but no concentration or weights are given. It is to add citric acid to approximately equal amounts of NaCl, and then pour over hydrogen peroxide and then the gold should dissolve in that with a gentle heat. Can any chemists help me out - like what amount of citric and NaCl do I use, and what concentration of hydrogen peroxide. Or any easier recipes out there with easily available chemicals?